Here's a big Gibson guy in the Manayunk area: http://www.superiorguitar.com/ I've not used him (I guess they were too busy to return my phone call ), but I've heard good things about him, (also that he was expensive and there could be a substantial wait). I didn't like that they didn't bother to return my phone call for a repair on my ES-175. I don't care how big you are, it's just good form. But maybe you'll have better luck than I did.
If I were you, though, I'd take a drive to Jack Gretz at Magdon music (http://www.magdonmusic.com) and have him work on it. He's a luthier, and is also Gibson certified. He's a hell of a nice guy, and Magdon Music sells some really nice gear, so it's a nice place to tool around after the 2 hour drive. (They're near Scranton)
If you hear of any others, I'd be interested as well.
tim at superior can do good work, but he is quite fankly kind of a jerk! They repaired an amp for me, and it took forever. when I got in touch with them they claimed they had been calling me and e-mailing that it was done-which was a bunch of crap. Also he has kind of an attitude, and is pricey. I have had other guys tell me they stopped going because he just was sort of not pleasant to deal with.
There is a guy named Tim Cloonan who builds basses under the name 'callowhill' instruments. He is a friend of mine and apprenticed under bill comins. he does some repair work on the side and is really skilled. He sometimes is too busy building to take on lots of repair work, but often he can fit it in pretty quick and always is very affordable. I have never used Ron Ruggerio but Tim says he is very good.